| In pathogenesis of arteriosclerosis, more attentions were paid to oxygen - derived free radidicals and lipid peroxidation. These substance may damage tunica intima of artery , and may be involved in the occurrence and progress of arteriosclerosis . Therefore, the more lipid peroxidation there are , the more tissues are damaged . In this way, the biomembrane could be suffered because it contain so many lipid.In this report, we detected the level of two antioxidase , phos-pholipjd hydroperoxide glutathione peroxidase (PHGPx) and superox-ide dismutase (SOD) , and some substance related to membrane damage , to present likely mechanism of coronary heart disease ( CHD ) and hyperlipemia.METHODSPatients were divided into three groups: (1) A group, 36 patients with CHD. (2) B group, 31 patients with hyperlipemia. (3) C group, 32 patients with CHD with concomitant hyperlipemia.30 healthy person made up D group for comparison.Activity of PHGPx, cu - znSOD, Na + - K+ ATPase and level of CD in erythrocyte of all person in four groups were detected respectively , and statistics analysis , including analysis of variance, t test and correlation, were used in this study.RESULTSthe level of PHGPx ,with unit of jxmmol/LNADPH/min. mgHb, in A,B,C and D groups were 3.78 ± 0.72,3.54 ±0.67, 2.90 ± 0. 80 and 7.04 ± 1.06 respectively, significant differece between very two of four groups were shown with P < 0.001. Activity of cu - znSOD (u/mgHb)were 1.67 ±0.08, 1.67 ±0.06, 1.54 ±0.114 and 1.96 ±0.14 respectively . the activity of Na+ - K+ ATP(ummol/pgHb) were 18.67 ± 2.13 , 20.19 ± 2.13 , 16.76 ± 2.35 and 27.7 ± 2. 51 respectively. The level of CD (nmol/mgHb)were 1. 11 ± 0. 11 , 1. 26 ± 0.12 , 1. 38 ± 0.13 and 0. 81 ±0.09 respectively. For each one, there also were significant difference.There were negative correlation between PHGPx and CD with r value of -0.76 ( p <0.05 ) ,and positive correlation between PHGPx and Na+ -K+ ATPase with r value of 0.71( p<0.05 ).DISCUSSIONmany evidences suggested that lipid peroxidation be involed inthe process of arteriosclerosis. It could be summarized in this way:Unsaturated fatty acid in biomembrane may be peroxidated by oxygen- derived free radidicals, lipid peroxidation can change due structureand function of smooth muscle of blood vessel , which results in in-creasing permeability. So it is easy for single uncleus macrophage to adhere and penetrate tunica intima of artery. Then proliferation of smooth muscle cell happen and fibrous plaquef appear. After that, Synthesis of prostacyclin, endothelium - derived diastole factor and Plasminogen activitor reduces , and the function of regulating retraction and relaxation of vessels declines ,and arteriosclerosis appears.PHGPx is one of the important protective factors , which can reduce phospholipid peroxidation on membrane, prevent lipid on membrane of mitochondria and microsome from being peroxidated. Additional, PHGPx catalysis oxidation reaction of sulfhydryl to decrease the hydroperoxide. So it serve as a barrier preventing from oxygen -derived free radidicals and it is one of the important protective enzymes for integrity of biomembrane.In our previous animal study, activity of PHGPx in erythrocyte may indicate that in endothelial cells of large artery wall , and it is easy to be detected. So for beings, we can estimate the activity of PHGPx in intima of vessel by detecting that in erythrocyte, which may be a potential method to research the correlation between PHGPx and diseases.The results shown that there were a significant drop in activity of PHGPx of patients with coronary heart disease ( CHD) and hyper-lipemia.The reduced activity of PHGPx may be a mechanism by which endothelial cells were damaged due to lipid peroxidated. But why it drop down is not clear . what was interesting is that the activity of PHGPx in patients with CHD with concomitant hyperlipermia was lower than that of patients with simple CHD or hyperlipermia. This stacking effect farther confirm it...
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